Method and device for the autonomous production, preparation, and supply of breathing gas to divers at extreme depths

ABSTRACT

The invention relates to a fully closed circuit-pendulum-storage system wherein a given amount of a ready to breathe gas mixture made of various inert gases including hydrogen and oxygen is continuously conveyed between two highly pressurized gas containers. Initially, the required breathing gas leaves the pressurized gas container and reaches the circuit at a constant dosage according to the overdosing principle. The circuit consists of an inhalation bag, a diving helmet, an exhalation bag and a single or double pack CO 2  absorption filter. At a depth of 0-100 m a mixture of oxygen, nitrogen and helium is used as a breathing gas. At a depth of 100-700 m a given amount of hydrogen is mixed therewith according to the wishes of the diver, whereby the oxygen content should not exceed 3 vol. %. When the diver emerges from a depth of over 100 m, the hydrogen is removed from the breathing gas and from the circuit by means of palladium membrane diffusion or catalytic water conversion. The removal of hydrogen is controlled by hydrogen detectors. At this point only, the oxygen content can exceed 3 vol %.

FIELD OF THE INVENTION

A method for the production, enrichment, and supply of breathing gas todivers at depths from 0 to 1000 m and a fully autonomous back-worndevice for its implementation are invented.

DESCRIPTION OF RELATED ART

In the well-known open-circuit or semiopen-circuit rebreathers, gasconsumption increases strongly at depths greater than 50-100 m. The lossof breathing gas can be completely eliminated only by the use of closedcircuit.

DE-C-834 201 (Draegerwerk, Luebeck) is a self-mixing closed-circuitrebreather.

In the method, the quality of breathed-in, respectively breathed-out airis measured, and depending on the difference between these quantities,oxygen is fed-up.

GB A-2 208 203 (Carmellan Research Ltd.) is a self-mixing rebreather ofthe Rexnord CCR type. These rebreathers were designed following theappearance on the market of an American space mission waste productcapable of measuring with adequate precision and reliability the crucialpartial oxygen pressure. In a completely closed circuit the rebreatheris brought by the use of inert gas, at a surrounding pressure typical ofthe diving depth. Then, in accordance with the readings of the oxygensensor, it is adjusted at the desired O2 partial pressure which meansthat, in the course of the diving process, only the oxygen that hasactually been used by the diver is replaced.

In this method, the data for the oxygen partial pressure and thequantity of CO2 are processed and regullated by the software of thepersonal computer on the surface.

At depths greater than 50-100 m, the use of this self-mixingClosed-Circuit Rebreather (CCR) is almost impossible, for technical orsafety-related reasons. The major shortcomings are three:

The breathing-gas-mixing electronics which regulates the precise partialoxygen pressure in the used helium-oxygen mixtures, is not absolutelysafe; the diver pumps-out the breathing gas through the rebreather byhis own lungs, so as to remove the breathed-out CO2 from therebreather's closed circuit (at 300 m depth, the density of the gas is31 bars). In contrast to the open circuit, in the closed circuit, thecontinuous gas do not flows away, washing-out the abundant contaminants.At great depths, the allowed oxygen and carbon dioxide operation spacebecomes smaller and smaller, thus enhancing the risk of CO2 or O2intoxication.

OBJECTS AND SUMMARY

Another shortcoming: at depths of 200-500 m, the rebreather can be usedfor no more than 15-20 minutes for the lack of gas.

So, the innovation was underlaid by the task to construct a method forthe enrichment and purification of gas and the production of breathinggas mixture, depending on the respective diving depth. Simultaneouslywith this, adequate gas provision and protection had to be ensured, soas to supply the diver with the mixture of breathing gas needed atsmaller or greater depths. Based on this method, a fully autonomousback-worn diving rebreather had to be designed.

The innovative solution of this task is described through a completelyclosed circuit-pendulum-storage-system, a certain amount of ready-madebreathing gas mixture, consisting of inert gas (helium) and oxygen, iscontinously conveyed between two high-pressure gas containers (15, 29),whereas in the beginning, based on overdosing and constant dosageprinciple, the needed breathing gas mixture reaches the closed circuit,consisting of an inhalation bag (37), a diving helm (6), an exhalationbag (11), double pack CO2-absorption filter (16, 17). The advance of thebreathing gas along this closed circuit is speeded-up by a low-pressuremembrane pump (13). The breathing gas is cleared of CO₂ and othercontaminants, dried and warmed-up, enriched additionally with pureoxygen on constant dosage principle according to the admissible partialoxygen pressure for the respective depth, and enriched with inert gas oneventual loss. Finally, the excessive quantity of breathing gas ispumped-in by high-pressure compressor (23) (piston or diaphragm version)and stored at high pressure of 220-450 bar in one of the twohigh-pressurized containers (15, 29). After the whole quantity ofbreathing gas mixture has been stored in one of the containers, amagnet-valve (31) is switched over and the same process starts in thereverse direction—from the full container to the empty one.

In this way, a really completely closed circuit is created, in which theexpensive inert gas (helium)-oxygen-gas mixture is used 100%, andconsequently-with no loss. Gas supply in this system can be effectedmainly by a ready-made gas mixture, based on constant dosage principle,i.e. mechanically and not electronically; the electronics used willeventually play only a second part which greatly enhances divingsecurity. The enrichment of the breathing gas mixture with oxygenaccording to the admissible O2 partial pressure can be effected alsobased on consage princuple, wheras self-mixing automation will only playa second part.

Since the compressor (23) is powered by one or two electric motors withdirect current 12V/24V, having an overall power of 2 to 3 kW, which issupplied by one or more accumulators with electric capacity between 100and 600 or more ampers per hour, the duration of diving will no longerdepend on breathing gas but on the electric capacity available. Thus,diving times from a couple of hours for depth of 700-800 m, to 24 ormore hours for small depths are provided; a prerequisite for this is theregular change of CO2 filters; the diver can be supplied additionallywith power by an electric cable from the surface, a submarine or asubmarine station, which is much more effective than hose supply. Thedifference is that the diver can switch this connection on and off atany time, cable supply being much lighter, more compact, and safer thanhose supply.

This method possesses many more advantages: the compressor and theelectric motors are oil-cooled, whereas the heat thus released is madeuse of by a thermal exchanger, producing hot water; in this way, thediver, the breathing gas, and the rebreather are kept warm which isextremely important for diving; by an additional equipment, comprisingone or two electric motors with overall power of 0,3-0,5 kW, 12V/24V,the diver can advance at the speed of 4-6 knots at a distance of 30-200km, depending on the capacity of the accumulator current. Thepossibility also exists for continuous use of light, photo, TV, video,navigation, speaking, diving-computer, deko-stops-computer, and otherequipment, all known-so-far types of electric and hydraulic-mechanicalinstruments and devices. Last but not least, stands the possibility forthe rebreather's switching over to some of the operating principles ofthe rebreathers known-so-far: open system, semi-closed system, closedsystem with mixed gas circulating in the closed circuit with automaticenrichment of the O-2, even closed system with pure oxygen gascirculating in the closed circuit, whereas with the latter all necessarymeasures should be taken for the safety of diving with oxygenrebreathers. These systems are optionally used, depending on the taskset, the switching on and off of the high-pressure connection with thecompressor, or if necessary—depending on the lost of the electriccapacity, the damage or absence of the electric motors or the compressor(as an emergenccy system).

This new pressure-pendulum-storage system makes it possible to supplythe diver with different breathing gas mixtures at depths from 0 to700-800 m for a relatively long period of time. The method has evenpotential for depths of 1000 m and more, and can be used even when the700 m limitations for diving depth are relieved by science.

The long-term application provides for quick diving without a divingcamera (Bounce-Diving) at depths up to 300-350 m, and free emergence tothe surface, observing the emergence time (deko-stops) or leaving asubmarine at a definite depth, for instance 300 m, operating at 600-700m, and then going back on one's own. A portable cable drum with a winschis equipped, providing the diver with the opportunity to optionally ornecessarily establish voice and electric communication with the surface.

The compact structure of the rebreathers, based on this principle,allows for diving directly from the beach, a boat, a ship, a submarine,a submarine station, an airplane or even by parachute jump. The devicecan be used for trade, sports, military, scientific, archaeological andother purposes. Totally new prospects and application fields emerge asto the military and other tasks. For instance, now it will be possiblefor the first time to organize not only small sabotage reconnaissancegroups, but whole divisions of a couple of thousand diving marines, tomaster the great depths of 0-1000 m, to operate within a field of reachof 100-200 km, to carry and apply all available types of weapons, toadvance at a great speed between 6 and 10 knots ore more.

Simultaneously with this, the innovation makes it possible for anyprivate person to use the device, reaching on one's own great depth withlittle effort to look for treasures, deal with sport, archaology etc.

The innovation provides for the further development of some branches ofsea study and sea industry, for instance, the direct extraction ofmanganese, petrol and gas at sea depths of 700 m (in future, eventuallyat 100 m or more).

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of a first exemplary embodiment of a systemand method for providing breathing gas to a diver.

FIG. 1 a is a schematic view of a second exemplary embodiment of asystem and method for providing breathing gas to a diver.

FIGS. 2(a-d) are front, side, top, and bottom views of the firstexemplary embodiment of the system and method for providing breathinggas to a diver.

FIGS. 2(e-g) are front, side, top, and bottom views of the secondexemplary embodiment of the system and method for providing breathinggas to a diver.

FIG. 3 includes side, back, and top views of a diver wearing the firstexemplary embodiment of the system and method for providing breathinggas to a diver.

FIG. 3 a includes side, back, and top views of a diver wearing thesecond exemplary embodiment of the system and method for providingbreathing gas to a diver.

FIG. 4 is a table showing the increasing volume of breathing gasrequired by a diver as the depth of the diver increases.

FIG. 4 a is a table showing the increasing amount of energy required todeliver an increasing volume of breathing gas to a diver as the depth ofthe diver increases.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The operational principle of the method and the autonomous back-worndiving rebreather implementing it are shown in greater detail in FIG. 1.

According to a first exemplary embodiment, illustrated by FIG. 1, thepressurized containainer (a steel bottle with mixed gas) (29), the gasflows out through the open valve and the high-pressure connection to theone-stage pressure reductor (30) for being reduced to above-crucialpressure up to 110 bar, depending on the diving depth. Then, through thedozing nozzle (39), the gas heads for inhalation bag (37) or directly todiving helmet (6) from where it reaches the respiratory organs of thediver.

During the exhaling phase, the gas flows backward through exhalation bag(11) or directly from diving helmet (6) into the two absorption filters(16, 17), from where it is drawned into by the low-pressure membranepump (13), and through non-return valve (35) it flows into inhalationbag (37) again. Thus, the circuit is closed. The low-pressure membranepump (13) is activated by electric impulses; its role is to continuouslyforce the breathing gas into this closed circuit, so that the diverexperiences smaller breathing resistance, hence relieved breathing withthe compressed gas.

The excessive gas, amounting from 10 to 100 normal l/min, depending onthe diving depth, does not leave the device's closed circuit throughoutlet valve (10) into the surrounding water (as is the practice in thesemi-closed systems) but is pumped into by compressor (23), compressedand stored at high pressure 220-450 bar through the triple valve (31),in the second mixed gas container (15), the latter being empty in thebeginning.

The compressor (23) is of the piston- or, the preferred version beingmembrane-hightension-compressor with power of 220-450 bar pressure,pumping and delivery power between 10 and 100 l/min, powered by twoelectric motors with direct current 12V/24V (21, 24), and overall powerof 2 to 3 kW. The electric motors are powered by one or moreaccumulators (19, 26) with 12V/24V direct current and capacity from 100to 600 Ah or more, depending on the design. The accumulators can be ofthe type lead/acid, nickel/cadmium, or silver/zinc. They are housedwithin oil boxes to equalize the pressure.

Compressor (23) compresses the excessive breathing gas through filter(18), which consist of condensate-separator, oil filter (with pistoncompressor), contaninant absorber, odours- and drying filter, whereasthe excessive breathing gas is purified and stored in the secondmixed-gas container (15) under pressure of 220-450 bar.

The device is designed for 16 or 18 main regions of deep diving. To eachof these regions, a definite dosage and a definite gas mixture isassigned. The assigned quantity of gas mixture remains constant,regardless of the diving depth. These 16 or 18 deep diving regions areshown on Tables I and II.

The gas flow into inhalation bag (37) is effected automatically or isoptionally manually regulated by dosing valve (39) of the breast-worncontrol panel (1), and can be set at 10 l/min (0-50 m) to 95-100 l/min(600-700 m), depending on depth.

The outflow of the gas mixture and the power of compressor (23) can alsobe effected automatically or can be regulated manually by the regulationof the electric current supply of the two electric motors (21, 24),through the switch-potentiometers (2, 40) of control (1), whereupon anamper-receipt from 24 to 200 ampers per hour is established. Accordingto this amper-receipt of the electric motors, the compressor can providepumping-in or supply power from 10 to 100 l/m. This quantity ofbreathing gas which is stored by the high-pressure compressor in thesecond container of mixed gas, is about 10-15% of the whole amount ofbreathing gas a diver needs per minute at the respective depth, theremaining gas continuing to proceed along the closed circuit. Thus, thedirect current used is economized for compressing and keeping the gasfor repeated use.

To avoid cases of emergency, and to prevent the appearance ofdifferences between gas inflow and the sucking power of the compressor,are dosing valve (39) and switch-potentiometers (2, 40) synchronized.Exhalation bag (11) is additionally supplied with safety valve (9)which, by closing, prevents that the compressor is pumping more thennecessary breathing gas out of the closed circuit or of the diver'slungs. Besides, safety valve (9) is supplied with switch-off automationwhich switches off electric motors (21, 21) in case of need. Inhalationbag (37) is supplied with demand gas regulator (36) which, in case ofneed, provides additional amount of breathing gas or, in someexceptional cases, provides for the overall system to be transferredinto an open-circuit rebreather.

Depending on the diving depth, and the needed gas mixture pumping powerof the compressor, motor circuit consumption respectively, the durationof diving and operation is between 3 hours for diving depths of 600-700m, up to 24 hours and more for diving depths of 0-100 m, depending onthe electric capacity of the electric accumulators.

Compressor (23) and electric motors (21, 24) are placed within a steelhousing and are oil-cooled. The generated heat is passed to the diverthrough thermal mixer (22) as 43-45° C. hot water to prevent him, thebreathing gas, and the rebreather from the cold of the deep.

The outlet valve (10) is switched on in case of quick emergence to thesurface or eventual differences between more then needed gas inflow andless sucking-in power of the compressor—the excess gas is exhausteddirectly into the water.

As the mixed gas container (15) is being filled with purified gas underhigh pressure (220-450 bar), triple valve (31) is switched over(automatically or manually), and the same process is repeated; this timethe pressure of the full mixing gas container (15) is reduced to theabove-crucial pressure of the compressed breathing gas, and throughdosing nozzle (39) of control panel (1) is supplied to the inhalationbag or directly to the diving helmet. The exhaled gas reaches againinhalation bag (11), then CO2-absorption filters (16, 17), after whichit is drawned-in by the low-pressure membrane pump (13), and then flowsback into the inhalation bag (37) through non-return valve (35). Theexcessive breathing gas is sucked in by the high-pressure compressor(23), purified by filters (18), and pumped in the now-empty mixed-gascontainer (29) under high pressure of 220-450 bar. The process could berepeated as long as there is certain accumulator electric capacity.

Additionally in this process, through the pressure-reductor anddose-nozzle (33), pure oxygen is supplied to exhalation bag (11) fromhighly-pressurized steel container (28), based on constant dosageprinciple, so that the oxygen share within the overall mixture be keptconstant within the admissible limits. Similarly to the dosing of mixedgas, the additional dosage and inflow of oxygen for the 16 main depthregions is constructed and established in such a way, so as to providecomplete synchron between the dosing of mixed gas and oxygen, ensuringfor the oxygen partial pressure to remain constant within the desireddepths.

In cases of emergency, when the compressor or the electric motors do notwork for one reason or other, the closed-circuit process can be fed-upby the low-pressure membrane pump (13) which operates on the principleof electromagnetic impulses or can be powered by a small electric motor,provided the accumulators have some electric capacity. Thus, the oxygeninflow from steel bottle (28) goes on, based on the principle ofconstant dosing. This is possible because there is enough of theoxygen-inert gas mixture, of course, for a definite period of timewithin the overal closed-circuit process: exhalation- and inhalationbag, diving helmet or mouthpiece, inhalation- and exhalation hoses,CO2-absorption filters, etc. (about 25-30 l volume in all, plus therespective depth pressure which, at 300 m for instance, is 31 bar; thismakes 900 normal volume liters in all). Then the diver can switch overthe device to the semi-closed circuit regime, thus providing for the useof the available amount of mixed gas.

To control the oxygen content of the breathing gas mixture, the deviceis supplied with sensors and meters of the oxygen content (12), and CO2(34).

In case of eventual loss, depending on the need, additional amount ofinert gas (helium) is taken from the steel container (27), and throughthe pressure reducer and dosing-nozzle (32) is fed to exhalation bag(11).

To overcome strong underwater streams or to provide for horizontal orvertical motion, an additional equipment is provided, comprisingelectric driving motors (20, 25) with overall power of 0.3-0.5 kW,12V/24V, which can allow the diver to move with velocity of 4-6 knots ormore. Based on the used accumulator capacity and the needed water depth,a distance of 30-200 km can be overcome, which attributes quite a newquality to diving.

To reduce the resistance of water and to increase velocity, additionalequipment is provided, consisting of different versions of specialstreamline covers that can be mounted on the basic device.

A specially-designed-for-the-purpose diving computer can prove quiteuseful, providing the diver with a continuous picture of all neededparameters: for instance gas inflow, gas dosage and stock, gas andenvironmental pressure, gas and water temperature, diving time,deko-stops, power of pumping-in and compressor supply, electriccapacity, O2 and CO2 contents, rotation number of the electric motors,water heating temperature, distance, velocity of water stream, velocityof motion, navigation parameters etc.

The cover of the device houses as well two or more lights, video, TV,and photo camera, ampermeter, and voltmeter, O2- and CO2-meter, a devicefor submarine voice communication, navigation and orientation devices.The rebreather can be additionally supplied with an electric cable and aglass-fibre cable, at the advantage that the diver can at any timeswitch off this connection, and switch it on after some time. The optionexists for the CO2-filters to be changed under water, one of themcontinuing to work meanwhile. And last but not least, the cable andvideo-connection with the surface provides for the unique opportunity tocontrol and advise the diver in the course of his work; in case ofemergency, the device can be directly refunctioned into ROV (RemoteOperation Vehicle) by the control office, and if the diver cannot dothis himself, be moved to a submarine or station by the use of thedriving motors.

The device can be produced in more than 10 different versions andmodels, differing by the capacity of the accumulators and the steelbottles, power of the motors and compressors, dimensions, form, size,and purpose of use.

Under water, the device has neutral weight, and above water it weighsbetween 50 and 150 kg; the device can be lifted above water only by theuse of a small crane or can be brought to water on small rollers. Itsdimensions vary as follows: length about 450-800 mm, width about 450-500mm, height about 250-300 mm. It provides for the diver's entering intowater through a hatch with internal diameter of 700-900 mm. All parts ofthe device are protected by a streamline cover, made ofglass-fiber-strengthened poliester tar or nirosteel tin, preventing itfrom mechanical damage.

In this method, and the implementing it autonomous back-worn rebreather,designed for the autonomous production, enrichment, and supply ofbreathing gas to divers at depths of 0-1000 m, in one closed circuitpendulum-storage system, a definite quantity of ready-made gas mixture,consisting of one (or more) inert gas and oxygen, is continuouslyconveyed between two high-pressurized containers (15, 29), whereas inthe beginning, the needed breathing gas enters, based on the overdosingand constant dosage principle, the closed circuit, consisting ofinhalation bag (37) a diving helmet (6), exhalation bag (11), and adouble pack of CO2-absorption filters (16, 17). The advance of thebreathing gas along this closed circuit is speeded-up by a low-pressuremembrane pump (13); the breathing gas is cleaned of CO2 and othercontaminants, dried and warmed-up; then, it is additionally enrichedwith pure oxygen according to the admissible oxygen partial pressure forthe respective depth, based on constant dosage; it is also enriched withinert gas (or inert gas mixture) on eventual loss; finally, theexcessive quantity of breathing gas is drawned-in by a compressor underhigh pressure (23) (piston- or diaphragm construction), and is storedunder high pressure of 220-450 bar in one of the two highly-pressurizedcontainers (15 or 29), After the whole quantity of breathing gas mixturehas been stored in one of the high-pressurized containers (15 or 29), amagnet-valve is switched-over and the same process starts in the reversedirection-from the full to the empty container.

The high-pressure compressor (23) is powered by one or twodirect-current electric motors (21, 24) which, on their part, arecurrent-supplied by one or more accumulators (19, 26). Thus, theduration of diving depends no longer on the available breathing gas buton the available current capacity. The compressor (23), and electricmotors (21, 24) are oil-cooled, and the heat thus generated is usedthrough a thermal exchanger (22) for the production of hot water whichreaches the diver and the rebreather. The rebreather is also suppliedwith one or two electric motors to move the diver in the horizontal orvertical direction with speed of 6 or more knots at a distance of 30 to200 km. The diver can at any time establish communication with thesurface by a cable, to use all electric and hydraulic-mechanicalinstruments known-so-far, to have continuously in his disposition light,photo, video, navigation, computer and other types of equipment, beingable to stay under water for 24 hours or more.

In diving under hyperbar conditions at depths greater than 300-400 m,the respiratory function is intensified because of the higher density ofbreathing gas which results in a drastic reduction of the diver'sabilities. For the execution of average-heavy or heavy work at depthsgreater than 400 m, man orients himself towards hydrogen as inert gas.

The oxygen-helium-hydrogen breathing mixture, called “hydromix” hasdensity which is about 42% smaller than the density of the gasesused-so-far. It relieves the diver's respiration, and allows to workunderwater at sea depths of 400 to 1000 m.

Diving with “Hydromix” breathing gas is delivered by a transport cameraand hose supply. No autonomous rebreathers, using “Hydromix” asbreathing gas are known so far.

According to a second exemplary embodiment, the newpressure-pendulum-storage method for the autonomous production,enrichment and supply of breathing gas to divers at small or extremedepths, described in the first exemplary embodiment, allows for the useof individual inert gases or different inert gas-oxygen mixturesincluding hydrogen.

When using hydrogen, certain safety measures must be taken. It iswell-known that, without the needed content of 4 Vol. % oxygen, hydrogencannot ignite. That is why, the oxygen content of maximum 3 Vol. % mustnot be exceeded which means that the breathing gas mixture of oxygen,helium, and hydrogen can be used only at depths of 50 to 700 m (infuture, eventually up to 1000 m). To use the same breathing mixturewithout hydrogen at depths of 0-50 m, with increased oxygen content,hydrogen must be removed from the mixture by separation or catalyticburning.

The separation of hydrogen from helium can be made by a paladiummembrane-diffusion cell. Only after hydrogen has been completelyseparated from the breathing mixture, can the oxygen content beincreased to 4 Vol. %.

The most important property of the of the second exemplary embodiment,as illustrated in FIG. 1 a, is the fact that the process of theready-made gas use, enrichment of the used gas, production of new gasand its storage under high pressure in one of the two high-pressurizedcontainers (15, 29) is effected within a period of 20-30 min or more.Meanwhile, the diver can use automatically or manually certain inertgases, combine different inert gas mixtures, observe the inert gasproduction and oxygen-encrichment process, control it, and if necessary,correct it.

In relation with the use of hydrogen as a possible breathing gas in thenew pressure-pendulum-storage method, another use is also possible whichrefers to energy—and power supply of the autonomous back-wornrebreather, namely the power-electric-supply by a fuel cell. Mostsuitable for the purpose are the alkaline fuel cells (AFC) which, ashigh-efficient current-producing electro-chemical sources, are suppliedwith pure oxygen and pure hydrogen. When placed in apressure-compensated-for vessel, the fuel cell can be supplied with theavailable hydrogen and oxygen, and in this way can power-supply the newrebreather in the course of many hours.

Other types of fuel cells (hydrogen-air) are also possible, combinedwith the new type of lithium-ion accumulators which can substantiallyimprove power supply.

In relation wth the use of the different inert gas mixtures with oxygen,hydrogen including, the operation principle of the newpressure-pendulum-storage method is considered in greater detail in FIG.1 a.

The rebreather operates at depth up to 200 m, according to the method,described in the main patent. Above this depth it is possible, by thediver's choice, to add additionally to the mixture breathing gas(consisting of helium and oxygen), certain controlled amount ofhydrogen, based on constant dosage principle, out of thehigh-pressurized gas container (16-a), through a high-pressureconnection to a one-stage pressure-reducer and dose-nozzle (10-a)directly into the mixing chamber (27-a) where it gets mixed with theinflowing inert gas helium and the respective oxygen share (less than 3Vol. %), based on constant dosage principle, gets pumped-in theexplosion-proof compressor (23), and is stored under high pressure(220-450 bar) in the empty high-pressurized container (15). This processtakes about 20-30 min, until the whole quantity of helium, oxygen, andthe dosed quantity of hydrogen are stored in the high-pressurizedcontainer (15). The precise dosing of hydrogen is effected by aflow-controller (17-a).

Immediately afterwards, the valve of the pressurized container (6-a) isclosed, the 4-stage valve (31) is automatically or manually switchedover, and this time from the pressurized container (15), the pressure ofthe prepared breathing gas is reduced up to above-crucial pressure, andthrough doze-nozzle (39) of the control panel (1), it is transferred tothe inhalation bag (37) or directly to the diving helmet (6). Theexhaled breathing gas is brought to the closed circuit, consisting of:exhalation bag (11), CO2-absorption filters (16, 17), a membranelow-pressure pump (13), inhalation bag (37), and diving helmet (6). Theexcessive breathing gas is pumped-in by the compressor (23). The oxygencontent is fed in dosed quantity, based on constant dosage principle tothe mixing camera (27-a), then the breathing gas is transported from thecompressor (23) under high pressure to the filter (18), where thecleaned and dried up gas if finally stored under high pressure in thenow empty container (29).

The oxygen dosing and control is effected additionally by aflow-controller (17-b).

If the diver has to emerge above the depth limit of 100 m towards thesurface (it is possible to emerge to a depth of 50 m with minimal oxygenquantity of 3 Vol. % in the breathing gas), it is absolutely necessaryto remove hydrogen from the breathing mixture or to use anotherbreathing mixture. The separation can be done in the diffusion cell(18-a) by the use of palladium membrane. Hydrogen diffuses through thismembrane at temperature of 280° C., and can be stored by the use ofhydride-storer or can be catalitically transferred into water. Theoxygen still contained in the breathing gas reacts with hydrogen at thepalladium-membran into water and is released with the flowing-outhelium. Helium and water in the gaseous form are transported throughfilters (18), where the breathing gas gets dried-up, and stored underhigh pressure in one of the two pressurized containers (15 or 29). Sincethe breathing gas contains no more oxygen, so oxygen is transported,based on constant dosage, directly into the respective pressurizedcontainer (15 or 29), through the valve and dosing nozzle (30-a). Inthis way, hydrogen is removed from the breathing gas after severalrelease cycles. In order to be sure that there is no more hydrogen inthe breathing gas, hydrogen detectors (19-a and 26-a) are installed, aswell as 2 oxygen-meters (19-b and 26-b).

The complex process of hydrogen separation can be needless if a mandives with the rebreather at depths from 100 up to 700 m and back till100 m.

In the diving region of 0-600 m, instead of hydrogen, different gaseousmixtures can be used, consisting of oxygen, nitogen, and helium. Atdepth of 0-50 m, different gaseous mixtures based on the oxygen-nitrogencombination, are possible.

For the purpose of better power-supply, instead of accumulator (19), inthe compensated-under-pressure vessel, an alkaline fuel cell can beadded. It is supplied with oxygen from pressurized container (28), andwith hydrogen from pressurized container (6-a). The possibility alsoexists for a hydrogen hydride-preserver to be installed in theaccumulator's place. In this way, the power-supply, and respectively thediving time of the rebreather are considerably improved. The availablehydrogen can be made use of by catalytc burning for the production ofhot water to warm-up the breathing gas, the rebreather, and the diver.

Additionally, on the rebreather are mounted vertical electrically-drivenmotors with propellers (20-a and 25-a) to provide for a bettermanoeuvring of the diver in the vertical direction.

In this method, and the implementing it autonomous back-worn rebreather,designed for the autonomous production, enrichment, and supply ofbreathing gas to divers at depths of 0-1000 m, in one closedcircuit-pendulum-storage system, a definite quantity of ready-made gasbreathing mixture, consisting of different inert gases and oxygen, iscontinuously conveyed between two high-pressurized containers (15, 29),whereas in the beginning, the needed breathing gas is supplied by thefull container, based on the overdosing and constant dosage principlewithin the closed circuit, consisting of inhalation bag (37), a divinghelmet (6), exhalation bag (11), and one or two CO2-filters (16, 17).

At depths of 0-100 m, the used breathing gas is a mixture of oxygen,nitrogen, and helium; at depths of 100-1000 m, by the diver'spreference, a definite quantity of hydrogen is added to the breathingmixture, whereas the oxygen content must not exceed 3 Vol. %.

The advance of the breathing gas along this closed circuit is speeded-upby a low-pressure membrane pump (13); the breathing gas is cleaned ofCO2 and other contaminants, dried and warmed-up. Finally, the excessivebreathing gas is enriched with pure oxygen according to the admissibleoxygen partial pressure for the respective depth, based on the constantdosage in the mixing camera (27-a); it is mixed with different inertgases (hydrogen including), in case of necessity or on eventual loss,based on the constant dosage; then, it is pumped-in by a compressor (23)(piston or diaphragm construction), and stored under high pressure(220-450 bar) in one of the two high-pressurized containers, which atthe beginning is empty s (15 or 29). After the whole quantity ofbreathing gas mixture has been stored in this container, themagnet-valve (31) is automatically or manually switched-over and thesame process starts in the reverse direction—from the full vessel to theempty one under pressure.

The high-pressure compressor (23) is driven by one or two direct-currentelectric motors (21, 24) which are current-supplied by one or moreaccumulators (19, 26) or by an alkaline fuel cell (AFC) (19). The fuelcell is powered by the available pure oxygen and pure hydrogen, and isstored in a pressure-compensated-for vessel.

In case of emerging at a depth smaller than 100 m, hydrogen is removedfrom the breathing gas and the closed circuit through apalladium-membrane diffusion cell (18-a) or is catalytically transformedinto water. The removal is controlled by the hydrogen detectors. Onlythen is the oxygen content enriched above 3 Vol. %.

1. A method for the autonomous production, enrichment and supply ofbreathing gas to a diver, the method comprising the steps of:continuously conveying between at least two pressurized containers abreathing gas mixture which comprises an inert gas and oxygen, whereinthe at least two pressurized containers are a part of a closed circuitsystem; conveying the breathing gas mixture from one of the at least twopressurized containers to a breathing area; exhaled breathing gasmixture is then conveyed to a carbon dioxide absorption filter by meansof a low pressure membrane pump wherein a portion of carbon dioxide isremoved from the breathing gas mixture exhaled by the diver by thecarbon dioxide filter; enriching the exhaled breathing gas mixture withoxygen, based on constant dosage according to an admissible partialoxygen pressure for the respective depth, to compensate for loss;exiting a portion of the breathing gas mixture, the portion of thebreathing gas based on an overdosing and constant dosage principle;transferring the exiting portion of the breathing gas to another one ofthe at least two pressurized containers and storing the exiting portionin the another one of the at least two pressurized containers at apressure of between 220 and 450 bar; and reversing the flow of thecontinuously conveyed breathing gas when the another of the at least twopressurized tanks becomes full such that the continuously conveyedbreathing gas is transferred to the less full one of the at least twopressurized containers.
 2. The method for the autonomous production,enrichment and supply of breathing gas to a diver of claim 1, furthercomprising the step of drying and warming the breathing gas mixture. 3.The method for the autonomous production, enrichment and supply ofbreathing gas to a diver of claim 2, further comprising the step ofwarming the diver with heat from a fluid wherein the fluid is heated bytransferring heat generated by the compression of the dried, warmed, andenriched breathing gas to the fluid.
 4. The method for the autonomousproduction, enrichment and supply of breathing gas to a diver of claim1, further comprising the steps of: providing an additional quantity ofbreathing gas to the diver from a demand regulator on an inhalation bag;and releasing excessive breathing gas from an outlet on an exhalationbag to surrounding media.
 5. A system for the autonomous production,enrichment and supply of breathing gas to a diver comprising: twopressurized containers connected to one another such that fluid is ableto flow between the two pressurized containers, the two pressurizedcontainers comprise a closed circuit storage system; a breathing gascomprising inert gas and oxygen contained in the two pressurizedcontainers; a low pressure membrane pump for transferring a portionbreathing gas after the portion of the breathing gas is exhaled by thediver; a carbon dioxide absorption filter for receiving the exhaledbreathing gas by the low pressure membrane pump and for removing aportion of carbon dioxide from the breathing gas exhaled by the diver bythe carbon dioxide filter; means for delivering a supply of pure oxygento the system for enriching the filtered breathing gas exhaled by thediver, wherein the supply of the pure oxygen added is based on aconstant dosage according to the admissible partial oxygen pressure forthe respective depth; a compressor for compressing the enrichedbreathing gas into a less full one of the two pressurized containers ata pressure of between 220 and 450 bar; a flow control means forreversing the flow of the breathing gas when one of the at least twopressurized tanks becomes full such that the continuously conveyedbreathing gas is transferred to the less full one of the at least twopressurized containers.
 6. A system for the autonomous production,enrichment and supply of breathing gas to a diver of claim 5, whereinthe low pressure membrane pump includes electromagnets driven byelectric impulses.
 7. A system for the autonomous production, enrichmentand supply of breathing gas to a diver of claim 5, wherein the lowpressure membrane pump includes an electric motor.
 8. A system for theautonomous production, enrichment and supply of breathing gas to a diverof claim 5, wherein the compressor is one of a piston version minicompressor and a diaphragm version mini-compressor outputting as much as150 L/min.
 9. A system for the autonomous production, enrichment andsupply of breathing gas to a diver of claim 5, wherein the compressor ispowered by two direct-current electric motors operating at 12V/24V, 2 to3 kW, and 2000-3000 U/min.
 10. A system for the autonomous production,enrichment and supply of breathing gas to a diver of claim 5, whereinthe compressor is powered by at least one accumulators 12V/24V withcapacity of at least 100 Ah and the accumulators are housed in oilfilled boxes.
 11. A system for the autonomous production, enrichment andsupply of breathing gas to a diver of claim 10, wherein the accumulatorsare of the lead/acid type.
 12. A system for the autonomous production,enrichment and supply of breathing gas to a diver of claim 10, whereinthe accumulators are of the nickel/cadmium type.
 13. A system for theautonomous production, enrichment and supply of breathing gas to a diverof claim 10, wherein the accumulators are of the silver/zinc type.
 14. Asystem for the autonomous production, enrichment and supply of breathinggas to a diver of claim 10, wherein the accumulators are of thelithium-ion type.
 15. A system for the autonomous production, enrichmentand supply of breathing gas to a diver of claim 10, further comprisingan alkali ne fuel cell for powering the system.
 16. A system for theautonomous production, enrichment and supply of breathing gas to a diverof claim 10, wherein the compressor and the two electric motors areplaced in a steel container and are oil-cooled by a heat exchanger fortransferring the heat to water wherein the heated water is supplied tothe diver at temperature of 45-50° C. to warm the diver.
 17. A systemfor the autonomous production, enrichment and supply of breathing gas toa diver of claim 5, further comprising: an inhalation bag with a demandregulator to provide an additional quantity of breathing gas in case ofneed; and an exhalation bag with an outlet valve to release excessivebreathing gas into the surrounding medium in case of need.
 18. A systemfor the autonomous production, enrichment and supply of breathing gas toa diver of claim 15, further comprising: a safety valve attached to theexhalation bag wherein the safety valve prevents flow of exhaledbreathing gas to the compressor and turns off the compressor if thepressure of the exhaled breathing gas is below a predetermined level;and a non-return valve attached to the inhalation bag wherein thenon-return valve prevents the flow of breathing gas from the inhalationbag to the compressor.
 19. A system for the autonomous production,enrichment and supply of breathing gas to a diver of claim 5, furthercomprising at least one propulsion unit powered by electricity from theaccumulators for moving the diver through the surrounding media in avertical and horizontal direction for a distance of at least 30 km. 20.A system for the autonomous production, enrichment and supply ofbreathing gas to a diver of claim 5, further comprising a controllerpanel adapted to display information to the diver and accepting inputsfrom the diver for controlling constant dosage of the breathing mixture.21. A system for the autonomous production, enrichment and supply ofbreathing gas to a diver of claim 5, further comprising a computeradapted to provide to the diver a picture of all needed parameterswherein said parameters comprise: gas inflow; gas stock; gas andenvironmental pressure; gas and water temperature; diving time;deko-stops; pumping and supply power of the compressor; availablecurrent capacity; oxygen and carbon dioxide content; rotation number ofelectric motors; temperature of heated water and supplied amount ofheated water; distance; velocity of water currents; advance velocity;and navigation parameters.
 22. A system for the autonomous production,enrichment and supply of breathing gas to a diver of claim 5, furthercomprising a winch having a cable drum, an inflatable floatation body, abliz-light, and quick detection antenna adapted to enable the diver toestablish, at any time and depth electric, video or audio connectionwith one of a surface of surrounding media and a control office.
 23. Asystem for the autonomous production, enrichment and supply of breathinggas to a diver of claim 5, further comprising a streamlined exteriorhousing adapted to reducing current resistance and achieving greatervelocity.
 24. A method for the enrichment and supply of breathing gas toa diver, the method comprising the steps of: conveying a breathing gasmixture, which comprises an inert gas and oxygen, from one pressurizedcontainer to a breathing area; conveying exhaled breathing gas mixtureto a carbon dioxide absorption filter by means of a low pressuremembrane pump; enriching the exhaled breathing gas mixture with oxygen,based on constant dosage according to an admissible partial oxygenpressure for the respective depth; filtering the enriched exhaledbreathing gas mixture using the the carbon dioxide filter to remove aportion of carbon dioxide from the enriched exhaled breathing gasmixture; conveying a first portion of the filtered breathing gas mixtureto the breathing area; conveying a second portion of the filteredbreathing gas mixture to another pressurized container and storing thesecond portion in the another pressurized containers at a pressure ofbetween 220 and 450 bar; and reversing the flow of the continuouslyconveyed breathing gas when the another pressurized tank becomes fullsuch that the breathing gas mixture is transferred to the less full oneof the two pressurized containers.
 25. A method for the enrichment andsupply of breathing gas to a diver, the method comprising the steps of:conveying a breathing gas mixture, which comprises an inert gas andoxygen, from one pressurized container to a breathing area; conveyingexhaled breathing gas mixture to a carbon dioxide absorption filter bymeans of a low pressure membrane pump; filtering the exhaled breathinggas mixture using the the carbon dioxide filter to remove a portion ofcarbon dioxide from the breathing gas mixture exhaled by the diver;conveying a first portion of the filtered breathing gas mixture to thebreathing area; enriching a second portion of the filtered breathing gasmixture with oxygen, based on constant dosage according to an admissiblepartial oxygen pressure for the respective depth; conveying the enrichedsecond portion of the breathing gas mixture to another pressurizedcontainers and storing the enriched second portion in the anotherpressurized containers at a pressure of between 220 and 450 bar; andreversing the flow of the continuously conveyed breathing gas when theanother pressurized tank becomes full such that the breathing gasmixture is transferred to the less full one of the two pressurizedcontainers.
 26. A system for the enrichment and supply of breathing gasto a diver, the system comprising: a first pressurized containerconnected to a second pressurized container such that fluid is able toflow between the two pressurized containers, the two pressurizedcontainers comprise a closed circuit storage system; a first conduitconnecting the first pressurized container to a valve; a second conduitconnecting the second pressurized container to the valve; a thirdconduit connecting the valve to a breathing area; a fourth conduit forconveying exhaled breathing gas; a low pressure membrane pump fortransferring the exhaled breathing gas through the fourth conduit; afifth conduit for delivering a supply of oxygen to the fourth conduitfor enriching the breathing gas exhaled by the diver; means forcontrolling the supply of the oxygen based on a constant dosageaccording to the admissible partial oxygen pressure for the respectivedepth; a carbon dioxide absorption filter connected to the fourthconduit for receiving the exhaled breathing gas and for removing aportion of carbon dioxide from the breathing gas exhaled by the diver; asixth conduit for delivering a first portion of the enriched andfiltered breathing gas to the breathing area; a compressor forcompressing a second portion of the enriched and filtered breathing gasinto the second pressurized container at a pressure of between 220 and450 bar; a seventh conduit for delivering the second portion of theenriched and filtered breathing gas to the compressor; a flow controlmeans for reversing the flow of the breathing gas when one of the atleast two pressurized tanks becomes full such that the breathing gas istransferred to the less full one of the two pressurized containers. 27.A system for the enrichment and supply of breathing gas to a diver, thesystem comprising: a first pressurized container connected to a secondpressurized container such that fluid is able to flow between the twopressurized containers, the two pressurized containers comprise a closedcircuit storage system; a first conduit connecting the first pressurizedcontainer to a valve; a second conduct connecting the second pressurizedcontainer to the valve; a third conduit connecting the valve to abreathing area; a fourth conduit for conveying exhaled breathing gas; alow pressure membrane pump for transferring the breathing gas throughthe fourth conduit; a carbon dioxide absorption filter connected to thefourth conduit for receiving the exhaled breathing gas and for removinga portion of carbon dioxide from the breathing gas exhaled by the diver;a sixth conduit for delivering a first portion of the filtered breathinggas to the breathing area; a compressor for compressing a second portionof the filtered breathing gas into the second pressurized container at apressure of between 220 and 450 bar; a seventh conduit for deliveringthe second portion of the filtered breathing gas to the compressor; afifth conduit for delivering a supply of oxygen to the seventh conduitfor enriching the filtered breathing gas; means for controlling thesupply of the oxygen based on a constant dosage according to theadmissible partial oxygen pressure for the respective depth; a flowcontrol means for reversing the flow of the breathing gas when one ofthe at least two pressurized tanks becomes full such that the breathinggas is transferred to the less full one of the two pressurizedcontainers.